There are many electronic devices capable of generating data that needs to be printed in document form. Devices such as computers, facsimile machines, digital cameras and copiers, medical imaging devices, optical scanners, satellite imaging devices, and scientific data collection devices, etc., typically employ a single processor to perform the various data collection, organization and print request functions. Unfortunately, when the processor is busy processing a print request, it is unavailable for other tasks. This problem occurs, for example, when the user of a personal computer requests multiple copies of a single document and then has to wait until the computer completes multiple print requests before he or she can again use the computer.
This problem has been addressed in systems that utilize background printing, i.e., printing which attempts to make the computer more available by processing print requests only during idle times for the processor. In this instance, a multi-page collated document printed “n” number of times would significantly slow down foreground processing of the user's document. Additionally, when the print job is sent repeatedly over a computer network to the printer, the response time of the computer network can be noticeably affected.
The problems associated with requesting multiple copies of a document in a printed job were largely solved through the introduction of Mopier® printers by HEWLETT PACKARD™. The operational features of the Mopier®, which are described in U.S. Pat. No. 5,764,863 entitled Multiple Original Copy Data Printer, provide a way to print multiple copies from a single transmission of only one copy of the document to decrease the use of network resources, computing time and storage space necessary for printing multiple copies or “mopies.” The term “mopy” stands for multiple original prints. A “mopy” is a reproduction of an original print that is bounded within a single job that a user sends to print. The original can be in either physical or electronic form, and the print job can be composed of “n” mopies. Each mopy may have “x” number of sheets. Both n and x may be one or more mopies and sheets, respectively.
However, one drawback is that without an on-board file system, the printer or other image-generating device cannot perform mopying functions. Many multiple original print (mopy) printers require a storage medium file system in order to properly perform the electronic collation functions. Many laser jet printers for instance, have flash devices that simulate a file system, or an actual EIO disk drive that is pluggable into the printer. If no on-board file system is available for mopying, the printer may default to non-collated copies. For example, a host computer may send a job requiring five copies of a three-page job. Because the printer does not carry an on-board file system, mopying is not possible. To compensate for this deficiency, the printer may convert the first image, page 1, into raster bits that are stored in a local RAM memory, which is subsequently printed five times. The printer may then drop the bits of the page 1 image, and convert page 2 into raster bits. Page 2 is then stored in the local RAM memory, and subsequently printed five times. The printer may then drop these page 2 bits and repeat the process for page 3. Alternatively, the printer may generate an error and not even attempt to print the job.